physics.fluid.concentric_reducer

Three distinct suites: educational examples on the calculator page, this legacy regression count (6/6 golden + boundary), and the CVP verification suite below. They are not the same number. Property, metamorphic, round-trip, O3, and interface statuses/checks are recorded in the CVP Manifest . SKIP (0/0) means that suite has no published vectors.

This calculator CURRENT · Public schema 1.0.0 matches · Semantic contract ✓ · Production attested · Public/cache ✓ · Origin ✓

CVP verification suite

Protocol checks from the Evidence Manifest. Distinct from the legacy regression suite above. Verification revision 2026-09-26.o2-o3. Calculation version 1.0.0. CVP 1.0.0-proposed. 4/4 golden · 1/1 CVP boundary · 2/2 invalid · 1/1 property · 1/1 metamorphic · 8/8 O3 · 2/2 cross-interface · 5/5 CVP contract. digest 7983105f1554. O2: concentric reducer K=0.5(1−A2/A1) vs a separate-module identity (≤2 ULP). Not C_c, not α, not (v1−v2)², not catalog K, not gradual contraction, and not Q=Av. ≤2 ULP vs O3 applies only to the published tabulated concentric-reducer vectors. Not catalog K, not pipe-entrance geometry, not sudden expansion (v1−v2)², not Darcy, and not Q=Av.

• Golden (oracle-backed) 4 / 4
• CVP boundary 1 / 1
• Invalid input 2 / 2
• Property 1 / 1
• Metamorphic 1 / 1
• O3 high-precision 8 / 8
• Cross-interface 2 / 2
• CVP contract 5 / 5
• Interfaces PASS · UI (SSR) / REST / MCP
• Interface claim ui-ssr is query-result HTML, not a live browser session. Error-path engine·REST·MCP 1/1 (status, code, calculation_version). SSR compared on URL-canonical requested calculations; empty query is idle (not an error) and JSON-typed object/array inputs are REST/MCP-only.
• Verified scope h = K v₂² / (2g) with K = 0.5 (1 − A₂/A₁); plus pressure and velocity solves; + O3 mpmath tabulated head.
• Assurance Engineering
• Deferred Not C_c, not α, not (v1−v2)² sudden contraction, not catalog K, not gradual contraction, and not Q=Av.

• release artifacts aligned PASS
• schema output required declared PASS
• schema valid input executes PASS
• engine success output validates schema PASS
• rest success payload validates schema PASS

Fingerprint sha256:627c335e0c8d2bccc5815f159d8197918e3d95056ce4d03b304a8b33d7722b47

Input schema sha256:4de7933ae44ef93289fdd4a502783dd2a4e17dead2f8209d7f01dd2a36de2435 · Output schema sha256:658188bba055812aea650f2c22cc7fe94e8ab6189a8b1f07f1e1b952e4f4e79a · Build-time SHA-256 digests prove published artifacts agree with each other (release_integrity.scope=workspace). Production attestation GETs canonical URLs twice (public/cached view and origin), including Capability HTML, via npm run attest:production --write (published at /.well-known/calculatorx-production-attestation.json) and fails if the public Capability page advertises a different calculation_version. This is artifact consistency, not an independent immutable release log.

Tool

concentric-reducer

Engine

concentric-reducer

Engine build

2026-09-24

Evidence core

2026-09-24T02:12:38.088Z

Rendered

2026-11-10T05:18:41.964Z

Last reviewed

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Assumptions

• Concentric reducer: h = K v₂² / (2g); K = 0.5 (1 − A₂/A₁); K referenced to downstream speed; K is reported, not an input
• A₂/A₁ in (0, 1); default g=9.80665 m/s²; default ρ=1000 kg/m³; incompressible; geometry from area_ratio or A1+A2 or D1+D2
• Not sudden expansion (v1−v2)², not gradual contraction α, not vena-contracta C_c, not catalog minor-loss K given, not a four-way cross, not Q=Av

Limitations

• Concentric reducer: h = K v₂² / (2g); K = 0.5 (1 − A₂/A₁); K referenced to downstream speed; K is reported, not an input
• A₂/A₁ in (0, 1); default g=9.80665; default ρ=1000 for Δp; incompressible; geometry from area_ratio or A1+A2 or D1+D2
• Not sudden expansion (v1−v2)², not gradual contraction α, not vena-contracta C_c, not catalog minor-loss K given, not a four-way cross, not Q=Av